(function (doc, win) {
  var docEl = doc.documentElement;
  var resizeEvt =
    "orientationchange" in window ? "orientationchange" : "resize";
  var recalc = function () {
    var clientWidth = docEl.clientWidth;
    if (!clientWidth) return;
    docEl.style.fontSize = (clientWidth / 375) * 16 + "px"; // 根据设计稿宽度调整
  };
  if (!doc.addEventListener) return;
  win.addEventListener(resizeEvt, recalc, false);
  doc.addEventListener("DOMContentLoaded", recalc, false);
})(document, window);
